Latency in IB clients

I have been testing the connection and latency of IB. For that I am running 2 ibtest instances withibtest.py --port 4002 --data EUR.USD-CASH-IDEALPRO --data1 USD.JPY-CASH-IDEALPRO --resample --timeframe Seconds --compression 5 --broker --trade --stake 50000
which are connected to the same IB gateway with different clientIds.

In ibtest.py I have only modified one line to see the system clock together with the logs. I was expecting both ibtest instances to produce logs almost at the same time, but as you can see from the logs below, the there is a lag between them. What might be causing one instance to be delayed so much compared to the other ibtest instance?